This invention generally relates to an hydraulic apparatus having means for automatically adjusting the positions of the headlights of a motor vehicle as a dependent function of the load on the axles of the motor vehicle and more particularly an apparatus in which the movement of the front and rear axles relative to the sprung motor vehicle body are oppositely sensed by means of a metering piston of a level sensor that is installed in proximity to each of the axles and the reactions of which are transmitted by means of positioning elements to the headlight housings.
Such an apparatus is generally known by the disclosure in DT-AS No. 2,014,280. In this apparatus, the level sensors and the positioning elements lie within a continuous conduit and the positioning elements are arranged in series. In such an apparatus it is not possible to incorporate thereinto additional elements that will permit manual operation of the headlight adjusting members.
On the other hand and by virtue of DT-OS No. 2,503,834, an apparatus with a hydraulic and manually effected adjustment is known in which a mechanically actuatable sensor is connected by way of two separate hydraulic lines that extend to the positioning elements of the headlight housings. However, such an apparatus is not adapted for automatic and load dependent operation.
There is also known by virtue of DT-OS No. 1,455,748 (see FIG. 2), an automatic and load dependent hydraulic apparatus in which, however, the rear axle level sensor requires a special converter.